Turn Off DFU on Startup (BLE Nano 2)



Just this morning I found this morning that the BLE Nano 2 is going into DFUTarg mode for around a minute when powered on before proceeding to my application. Before today it has not had this problem. Can anyone point me to where I can fix this so my application begins when powered on?


Did you get this fixed? I had a similar thing happen, all working well then, wham, into boot loader mode for 30 seconds every time it started up, really annoying.

I found that because I was changing some PIN modes, it obviously screwed something up with the boot loader on startup and the pull-up on D5 was not working and it was entering BOOTLOADER as that PIN was now not connected to anything but wasn’t being pulled-up…

SO TO FIX THIS, I added a 1K resistor, probably 10K will do it too from PIN D5 (P_04) to 3.3V and it works every time perfectly now… Try it if you haven’t got the problem fixed…

NOTE, D5 is held low during boot by a button to enter BOOTLOADER MODE, then it will stay in that mode for 30seconds then run you application if no Firmware Update is initiated.

Don’t know why the BOOTLOADER has ‘lost’ it’s PIN Settings for PULL_UP but it has, unless it’s damaged inside the chip or something…

Hope this helps.




Thanks for the help!

It turns out that with my problem it was because I updated to the 0.0.2 version of the Arduino Library. When downgraded to 0.0.1 version everything went back to normal.

I will give what you said a try though!